In vitro tissue cultivating plant propagation methods have become widespread in the last two decades. In the United States more than twenty and in West-Europa numerous propagating laboratories are operating in which between one hundred thousand and two hundred thousand plants are produced per month by means of the tissue cultivating process.
From the practical point of view the main features of tissue cultivating propagation are as follows: from the meristematic tissues of the sprout tips and root tips under sterile conditions, plants, free from all kinds of plants pathogens, can be propagated with a velocity which is several orders of magnitude higher than that of the conventional propagation method, with a significantly smaller area demand and consequently in a much more economical way than according to the conventional propagating methods.
In Hungary the large scale use of the tissue cultivating plant propagation method is under progress.
Although the tissue cultivating propagation is more economical than the conventional propagation methods, its inherent advantages can not be utilized owing to various drawbacks.
The major disadvantage of the tissue cultivating propagation method resides in the fact that while under in vitro conditions on unrestricted propagation of the plants takes place, when planted into the soil--depending on the type of the plant culture--about from 20 to 60% of the plants grown under sterile conditions are destroyed under the new, less favourable in vivo conditions [Broome, Zimermann: Hort. Science. 13, 151-153 (1978); Earle, Langhans: Hort. Science, 10, 608-610 (1975); Sutter, Langhans: J. Am. Soc. Hort. Science, 104, 494-496 (1979)].
Although several efforts were made to enhance the efficiency of propagation by improving the technical conditions of in vivo culturing (smaller temperature fluctuation, relatively high humidity), said measures failed to give the desired result.